SIP

SIP 199 Early Dialog Terminated vs 305 Use Proxy

SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 305 (Use Proxy) is a 3xx Redirection response. 199 indicates that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs. In contrast, 305 means that the requested resource must be accessed through the proxy given by the Contact header field.

Description

A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.

When You See It

In forked call scenarios when one of the forked branches is cancelled because another branch was answered.

How to Fix

No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.

Description

The requested resource must be accessed through the proxy given by the Contact header field.

When You See It

When the request must be routed through a specific outbound proxy server.

How to Fix

Resend the request through the proxy specified in the Contact header of this response.

Key Differences

1.

199 is a 1xx Provisional response, while 305 is a 3xx Redirection response.

2.

SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.

3.

SIP 305: The requested resource must be accessed through the proxy given by the Contact header field.

4.

You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.

5.

You encounter 305 when when the request must be routed through a specific outbound proxy server.

When to Use Which

For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully. For 305 (Use Proxy): Resend the request through the proxy specified in the Contact header of this response.

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